Syrian conflict
Three Spanish journalists are missing in Syria's northern city of Aleppo. In this photo, dated July 4, 2015, rebel fighters walk on the rubble of destroyed buildings on the western outskirts of Aleppo. Getty Images/AFP/Zeing Al-Rifai

Three Spanish freelance journalists reporting from Syria’s troubled northern city of Aleppo have gone missing, the Spanish press federation said Tuesday. They were last seen on July 13 but it's not yet clear if they have been kidnapped.

Antonio Pampliega, Jose Manuel Lopez and Angel Sastre entered Syria on July 10 through southern Turkey, according to a statement released by the Federation of Press Associations of Spain (FAPE). Spanish national television network TVE said that the missing journalists were on a joint investigative reporting assignment, according to Agence France-Presse (AFP).

Elsa Gonzalez, president of FAPE, reportedly said that Spanish government authorities informed her about the situation, adding: “They cannot yet conclude that they have been kidnapped.”

Rami Abdurrahman, director of the Britain-based Syrian Observatory for Human Rights, said late Tuesday that Pampliega, Lopez and Sastre were last seen on July 13 in a white van in Maadi district of Aleppo, the Associated Press reported.

Meanwhile, the families of the missing journalists reportedly said in a statement that, “an effort has been underway ... to search and locate them.”

Pampliega, a war journalist, reportedly worked in troubled countries such as Afghanistan, Iraq and Pakistan. He also contributed to AFP's text coverage of the civil war in Syria until 2013, according to AFP. Lopez, who also worked with AFP until 2013, is a photojournalist and has reportedly covered several war zones. The Madrid Press Association’s website reportedly showed that Sastre has contributed for Spanish television, radio and press while working from various troubled regions around the world.

At least 84 journalists have been killed in Syria since March 2011, according to the Committee to Protect Journalists, while others are missing or have been freed on ransom.